1. Field of the Invention
The present invention relates to emergency gas and electricity shutoff equipment and control systems therefor. In particular, the present invention relates to the shutoff of the flow of natural gas to a home or other point of use for reasons of safety during emergencies such as seismic events, fires, etc. The present invention further relates to apparatus and systems for shutting off the electricity at a home or other point of use under similar conditions.
2. State of the Prior Art
Various devices have been known in art for shutting off gas systems in the event of a seismic disturbance or the like. For example, U.S. Pat. No. 4,311,171 to Nobi requires a first ball to close a fuel line and at least a second ball, wherein the second ball is mounted within the casing so that a tremor would cause the second ball to dislodge the first ball from its pedestal. The ball for closing the fuel line is required to be mounted in a concave cup supported by a plurality of ball bearings, and includes a concave member as well as a resilient means such as a spring for biasing the cup against the concave member.
U.S. Pat. No. 4,565,208 to Ritchie requires the inclusion of a track and at least a ball riding in the track, and in addition requires the inclusion of xe2x80x9can obstructionxe2x80x9d which causes the ball to leave the track when a seismic disturbance causes the ball to contact to the obstruction with sufficient energy. It further requires the obstruction to include an incline surface that extends over the track and has a height which decreases across the width of the track.
U.S. Pat. No. 4,475,565 to Keller et al. discloses a magnetically actuable shock responsive unit. This unit includes a valve mechanism for shutting off the flow in a fluid line and is operable upon shock induced horizontal displacement of a weight relative to a support to actuate the valve. An electromagnet is provided for providing a separate actuation of the weight. Movement of the weight from its support to the side of the housing causes the weight to engage a movable tube that releases a mechanism that closes the valve.
U.S. Pat. No. 4,903,720 to McGill, one inventor of the present invention, discloses a safety shutoff device usable in any position. An inertia ball engages a first member so as to move the first member from a first position to a second position in response to vibrations or shocks imparted to the housing.
U.S. Pat. No. 5,119,841 discloses another safety shutoff apparatus using an inertia ball that normally rests on an indented surface. A lever is pivotally mounted with a permanent magnet mounted beneath the free end of the lever. When a shock or vibration causes the inertia ball to jump onto the lever and roll toward its free end, the inertia ball is attracted to the permanent magnet so as to cause the lever to be pivoted downwardly.
Further seismic safety valves are described in U.S. Pat. Nos. 5,409,031, 4,903,720 and 5,119,841.
The objects of the present invention are to generally improve the state of the prior art with respect to emergency shutoff, not only of the flow of gas to a point of use installation, but also of the supply of electricity.
According to a first aspect of the present invention, a gas meter and valve installation has gas supply plumbing for supplying gas to a point of use and point of use plumbing receiving gas from the gas supply plumbing. A gas meter has a gas inlet connected to the gas supply plumbing and a gas outlet connected to the point of use plumbing for metering the quantity of gas used at the point of use so that a gas supply passage is established through the gas supply plumbing, the gas meter and the point of use plumbing. A gas flow shutoff valve is positioned along the gas supply passage outside of the gas meter and has a valve member that is movable between an open position in which the gas supply passage is open, allowing for gas to flow through the gas meter and into the point of use plumbing, and a closed position in which the gas supply passage is substantially closed so that substantially no gas is allowed to flow into the point of use plumbing.
The gas flow shutoff valve preferably has a housing having a valve gas inlet and a valve gas outlet. One of the inlet and the outlet is connected to the gas meter and the other is connected to one of the gas supply plumbing and the point of use plumbing. A spacer having a spacer inlet and outlet is connected between the other of the gas supply plumbing and the point of use plumbing.
Preferably, the point of use plumbing includes a service tee having an inlet, an outlet and a service opening having a plug therein.
The gas inlet and the gas outlet comprise male inlet and outlet threads. The point of use plumbing or the gas supply plumbing has a union nut for connection with one of the male inlet and outlet threads. The gas flow shutoff valve is connected between the other of the point of use plumbing and the gas supply plumbing and the other of the male inlet and the male outlet threads. The gas flow shutoff valve has a nut thereon for connection with the other of the male inlet and the male outlet threads and a total height that is equal to the height of the union nut.
According to a second aspect of the present invention, a gas flow control system includes a gas passage including gas supply plumbing and point of use plumbing for receiving gas from the gas supply plumbing. A gas flow shutoff valve is positioned between the gas supply plumbing and the point of use plumbing, and is capable of closing in response to a gas flow shutoff signal. A controller remote from the gas flow shutoff valve is capable of generating the gas flow shutoff signal, and a communication link between the controller and the gas flow shutoff valve sends the gas flow shutoff signal to the gas flow shutoff valve.
The controller may comprise a seismic sensor for generating the gas flow shutoff signal, and/or a security system control, and/or a break away gas pipe portion positioned between the gas flow shutoff valve and the point of use.
A fuel cell can be used to generate electric power from gas flowing through the gas passage. For example, the fuel cell could provide electricity for an automatic meter reading device connected with a gas meter. The automatic meter reading device may have a communication link with the controller to send signals thereto representing gas usage.
The gas flow control system can also have an electric interface device installed at an electric meter box in communication by a communication link with the controller.
According to a third aspect of the present invention, there is provided an improved valve for shutting off a flow of gas. In this valve a housing has a gas inlet, a gas outlet and a gas passage therebetween. A gate mounted in the housing is movable in a direction across the gas passage between open and closed positions. The gate has a first portion having an opening therein positioned across the gas passage in the open position and a second portion positioned across the gas passage in the closed position. An upstream seat is mounted in the housing upstream of the gate, the upstream seat surrounding the gas passage and contacting the gate so as to form a seal between the housing and the gate on the upstream side of the gate. A downstream seat is mounted in the housing downstream of the gate. The downstream seat surrounds the gas passage and contacts the gate so as to form a seal between the housing and the gate on the downstream side of the gate.
According to a fourth aspect of the present invention, a gate valve for shutting off a supply of gas is spring biased toward its closed position. A release pin is movable between one position in which the release pin prevents the spring from moving the gate toward the closed position and another position in which the release pin releases the spring and the gate so that the gate moves to the closed position under the biasing force of the spring.
A reset member is interconnected with a gate for resetting the gate from the closed position to the open position. The reset member extends from a point outside of the housing to the gate and has an end received in an elongate slot in the gate. The slot has a stop member and an end thereof so that when the gate is in the closed position, the reset member can be pulled from outside of the housing so that the end of the reset member engages the stop member and pulls the gate from the closed position. The reset member is sealed from the outside by a dynamic seal in the housing. It further has a knob thereon positioned outside of the housing for manipulating the reset member, the knob having a static seal thereon for engagement with the housing.
The housing has a chamber adjacent to the gas passage, the chamber having a gate end through which the gate is movable and a spring end. The spring is compressed between the spring end and the gate in the open position. The gate includes a spring receiver on an end thereof in the chamber and receiving the spring therein. The release pin, in the open position of the gate, extends into the chamber and engages the spring receiver.
The release pin is moveably supported by a bushing and has an engagement end for engaging a member fixed with respect to the gate, a shaft portion slidable in the bushing and a stop for engaging the bushing in order to limit movement of the release pin. A connector in the release pin has an axial space therein. An actuator is provided for actuating the release pin, and includes a link member that extends into the axial space and is movable therein. When the actuator is actuated to move the gate to the open position, the link member axially moves a predetermined distance without engaging the connector of the release pin before engaging the connector of the release pin. The actuator includes a solenoid and a solenoid pin having a link member connected thereto. The solenoid pin is spring biased toward the release pin.
A status indicator may be provided on the exterior of the housing to indicate the open or closed status of the gate.
The member on the gate and the release pin may have respective complimentary engagement surfaces angled with respect to the direction of movement of the gate in order to make it easier for the gate to be actuated.
The release pin may also comprise a roller for engagement with the member fixed with respect to the gate. Further, the release pin may comprise a solenoid pin movably supported in the solenoid actuator by a plurality of rollers mounted on the solenoid pin.
According to another aspect of the present invention, a valve for shutting off a flow of gas has a magnet mounted with a gate of the valve. A solenoid actuator is provided for moving the magnet so that the gate is moveable between the open and close positions.
According to yet another aspect of the present invention, an electricity shut-off arrangement includes an electric meter box mounting an electric meter, a circuit breaker on the electric meter box for shutting off electricity and a pull chain on the circuit breaker. A shutoff device is connected with the pull chain for actuating the circuit breaker by pulling the pull chain. This device has a communication link for communicating with a remote controller for activating the shut-off device. Preferably a door is provided so as to be able to close over the shut-off device.
The shut-off device may comprise a spring-loaded rotatable arm for pulling the pull chain. This arm has a detention portion thereon for engagement with a release member. The release member is movable between a detention position in which the release member engages the detention portion of a spring-loaded rotatable arm to detain the spring-loaded rotatable arm in a spring-loaded position and a release position in which the release member releases the detention portion so that the spring-loaded rotatable arm can rotate and pull the pull chain.
In one preferred embodiment, the release member comprises a ball member. The detention portion preferably comprises an angled surface on the spring-loaded rotatable arm that biases the ball member away from it. A release pin is moveably mounted between a first position that prevents the ball member from moving, and a second position in which the ball member can move away from the detention portion. A solenoid actuator is provided for moving the release pin. Preferably a solenoid pin of the solenoid actuator will move and accelerate over a predetermined distance before actually engaging and moving the release pin.
According to another preferred feature of this aspect of the invention, the release pin has a second ball member that is rollably positioned thereagainst at a position opposite to the first ball member.
Alternatively, the release member may comprise a solenoid pin that is spring-biased into engagement with the detention portion of the spring-loaded rotatable arm. The solenoid pin has a solenoid actuator for moving the pin against the spring-biased in order to release the spring-loaded rotatable arm.
According to a further aspect of the present invention, an electric interface device is provided for placement between an electric meter and a meter box. The device has a pair of interface plugs for connection to receptacles of the meter box, a pair of interface receptacles for connection to a pair of electric meter plugs and an electricity shut-off for shutting off electrical connection between one of the interface plugs and the respective one of the interface receptacles. The interface plugs and interface receptacles are ordinarily electrically connected to each other. The electricity shut-off preferably comprises a connector that connects one of the plugs with one of the receptacles of the interface, and a solenoid actuator for moving the connector to break the electrical connection. The interface further includes a housing having a first interface flange for connection with a meter box flange and a second interface flange for connection with a meter flange. The interface may further include a communication link linking the electricity shut-off with a remote controller and an external power connection for supplying power to outside of the interface device.